Solar Thermal Systems

Solar hot water systems, also called solar thermal systems, utilize the sun’s energy by generating heat. This heat is stored in water. (By contrast solar PV systems generate electricity which is fed to the national grid or stored in batteries).

Solar Thermal Systems

The sun is the source of all our energy. This energy travels through the vacuum of space and is received on earth as radiation. When radiation (light) strikes matter the molecules of that matter vibrate causing friction and therefore heat. This happens even on a cold or cloudy day albeit to a lesser extent.

Solar collectors are selectively coated to absorb this light as completely as possible and minimize thermal radiation losses. Solar radiation is even present on cloudy and cold days and useful at all latitudes in all climates. By using vacuums and insulation it is possible to prevent much heat loss.

Traditionally, solar thermal systems have been used to heat water. The energy required to heat water (about 20% of the energy use) remains more or less constant throughout the year irrespective of the insulation levels of the building.

However, now that homes are better insulated (thanks to Building Regulations and policies such as the Code for Sustainable Homes) there is a reduced energy demand for central heating. Solar thermal systems are now able to provide a larger solar fraction of the overall hot water and central heating energy requirement.

This is achieved by the use of accumulators (a large thermal store) which acts like a battery of stored energy. The energy content of this 'battery' can be called upon to provide hot water and central heating. Energy contributions to the accumulator can be made by solar thermal, wood burning stove, traditional boiler, electric immersion, air source heat pump and ground source heat pump.

As fossil fuel prices rise solar thermal systems become more cost-effective. As consumers we can choose either to accept fossil fuel price increases or to offset them with help from the sun!!

See photographs of our installations here.

Solar ST Case Studies

Schuco flat plate

Schuco flat plate

.

Solar and air source heat pump

Solar and air source heat pump

.

Flat roof installation

Flat roof installation

.

'Landscape' installation

'Landscape' installation

.

Indoor Pool

Indoor Pool

.

East-west system

East-west system

.

Combi boiler + solar

Combi boiler + solar

.

Velux-style collectors

Velux-style collectors

.

Solar and ground source heat pump

Solar and ground source heat pump

 

Renewable Heat Incentive

The details of the Renewable Heat Incentive (RHI) have been finalized. We recommend you to look at the OFGEM website for further details:

In brief:

You will need to obtain an Energy Performance Certificate (EPC) for your house.

Solar thermal attracts a tariff (please check OFGEM website) and is RPI-linked.

Payments are made quarterly over 7 years based on deemed heat usage.

A typical solar thermal installation will deliver bewteen £1500 and £2000.

Read more

BENEFITS OF SOLAR THERMAL IN THE UK

Save money
Insolation in the UK is sufficient to provide an average of 60% of a household’s annual hot water requirements.  In the southeast it is not uncommon to get well over 90% of your hot water requirements between the months of April to September.  During the other 6 months the solar system can pre-heat the incoming cold mains water to between 20-40°C.  This means that your boiler has considerably less work to do.

Minimize your environmental impact
Burning fossil fuels produces vast amounts of carbon dioxide, a major contributor to global warming. The average household with a 3m² solar system installed can expect to generate approximately 2,256 kWh/year with zero emissions.